We need netlander

Doug

It was uploading as you posted that

http://www.unmannedspaceflight.com/doug_im..._461_p_anim.gif

800k

Doug

Sol 455 navcam movie
http://www.unmannedspaceflight.com/doug_im..._455_n_anim.gif

Sol 456 navcam movie
http://www.unmannedspaceflight.com/doug_im..._456_n_anim.gif

Sol 459 navcam movie
http://www.unmannedspaceflight.com/doug_im..._459_n_anim.gif

all approx 700kb

The last one is spectacular

Doug

A lap around Victoria? That would be something like 2.5km on its own

Doug

They probably did ping MTES at it from the Sol 454 Pancam position - it's a data-rich instrument so you can just keep scanning 24/7 - you have to have a target to aim at - and they only spotted this target essentially after driving past it

How I'd love to be sat on the ledge at Larrys Lookout, just watching Spirit do it's thing about 15 m away just above me over my right shoulder.

Doug

I'm AMAZED by the Magellan data volume - but to be fair, no interplanetary spacecraft has matched it's data rate ( up to 268.8kbps ) and the first to do so will be MRO

Doug

Perhaps there's scope for something like ESA provide the launcher and part of the instrumentation - NASA provide the relay capacity and the bulk of the spacecraft. Something in that mould must surely be possible - and sharing the cost between a mars scout budget and a small ESA project would make it not only fiscally possible, but might count as the soft-landing experience required by ESA before attempting the Exomars lander.

Doug

If they were prepared to enter Endurance with no g'tee of getting out - I think the same would be very much true of Victoria - especially if MiniTES is actually dead by that stage.

Doug

I suppose one good reason to do one MSL, and another in the following opportunity

If the first one augers in, the investigation board have about a year to make any change sugestions before the second enters ATLO

I still wish they'd find room for a netlander mission in the next 3 launch ops - it's ripe for an ESA/NASA colab like Huygens

Doug

I've not seen any skycrane numbers - i've googled and hunted till my mouse was screaming - but I think a reasonable figure would perhaps be 400-600kg? i.e. half that of an equiv airbag system

Doug

And then - in a backwards ESA move - I suppose a clone of the Venus vehicle could be flown to mars at a later date - or vice versa. Are Mars mission precluded from Discovery money?

Doug

Scaling of airbags I can answer.

Launch mass - 1062kg

Lander + Airbags - 365kg
Backshell - 198k
Heatshield 90kg
Cruise Stage 183kg
Fuel 52kg
Rover 174 KG

Ignoring the cruise stage and fuel load (as they dont need to scale with the rover - but everything else does) - you have 827kg hitting the top of the martian atmosphere - of which only 21% is the bit you care about.


MSL is planned to be 600kg - using that 21% model again (which is conservative given that the airbags scale faster than that for the mass of the payload) - gives you an entry mass of 2851kg

Allow for that mass will require 350% as much fuel for the TCM's during cruise - and that in turn will require approx 10% of THAT as extra fuel tanking etc - which gives us a total cruise stage weight of 183 CS + 182 Fuel + 18 tanking = 383kg Cruise stage.

So - total launch mass would be 3234kg - only just shy of the 3530kg of the Viking probes of the '70s which required a Titan IIIE launch vehicle to get to mars. Today this would require either an Atlas V 531, or top end Delta IV Med

Once you swallow the higher launch costs ( I think the Atlas V 401 of MRO is probably as big as they'll want to get in the near future ) you then have another problem...

Your payload has to survive anything up to 40G impacts from any direction on landing and sometimes, you just dont want that

As for confidence in the system - hands up if you thought that the MPF system of parachute, backshell, solid rockets, a bridle, airbags and bounce bounce bounce was a good idea before the summer of 1997. Hmm...no hands

I think I went thru this in that other thread - but I've been more verbose with the figures this time. Using airbags on a 600kg rover deisgn would result in a dead lander mass of 1258kgs that surves no purpose whatsoever after landing.


Doug

I can see where you're going and actually - I kind of see how the sled idea might make a little more sense now - have the rover wheels remain tucked as they are in the backshell - and from the bottom of the WEB - bring a few struts down to a small frame that runs under each wheel to act as a delivery 'pallet' as it were, perhaps no more than 2 or 3 inches tall. If you've seen stuff dropped out the back of a C130 transport plane you'll know what I mean.

Then - after that the rover simply has to push the wheels down / push the WEB up and drive straight off.

I still think the vital technological steps that need to be made are to have the skycrane be a stable and reliable platform in the hover - and have the ability to identify and navigate to an area without rocks or slopes over a certain magnitude - something which Airbags did simply on their own by rolling around. Imagine skycrane dropping a $800m rover onto the top of Humphrey rock, or Burns Cliff

As I understand it - the des imager wont be talking to the rover during des itself - it'll simply be turned on and recording data to its own buffer - which will then be transfered to the rover and downlinked after landing - so I dont think it's imagery could be used - in the current data flow design at least - to interpolate a safe landing site for skycrane to fly towards

Doug

People have asked if they can donate to help payfor hosting (I've spent about £200 in total on hosting fees and buying a licence for the Invision board - and no doubt popularity will increase hosting fees)

So - in response to that - if you look at the bottom left of the portal page...

http://www.unmannedspaceflight.com/index.php?act=home

You'll see a paypal donate button.

This is by no means a plea for cash - simply a response to people who asked if they could contribute in some way. In the message section of the donation process, if you leave a note telling me your username then I will change your user 'title' ( the bit under your name on each post ) to 'Contributing Member' or something similar. If you wish your donation to go un-noticed, just say so and I'll leave your title untouched.

For people who'd like to contibute without donating, I will soon be opening two stores. One will be at www.photobox.co.uk for some of the more popular mosaics. The rules there are that every penny over and above the price of printing goes to me - so I'll be doing something like a 25% markup. Similarly - I will open a Cafepress store with all the usual things like shirts, mousemats, mugs etc with the URL and logo on, hopefully in a stylish way

I hope that between these three things - I can avoid using onsite adverts to bankroll the cost of running the forum. And believe me - I will stick pins in my eyes and walk barefoot on broken glass before I have any pop-up, or animated adverts!

The only other thing I'm thinking of doing is taking my favorite mosaic of all (which many of you havnt seen here ) - and doing a limited print run of 10, which will be framed, numbered and signed - which will then go on Ebay - the revenue from the last of these will go toward my Comic Relief fund!

The store and the gallery will probably launch next week with a few items, and the range of items will increase over time as I re-edit and prepare imagery and graphics for the different sizes available.

I'll keep you all posted about how well all this does. I dont want to forum to be a profit making exercise - thats not why I do it - and I dont mind spending many many hours of my time making sure everything is running smoothly - but it'd be nice if it didnt cost me any money to run, and perhaps build up a small contingency for bigger, better hosting in the future.

I'd welcome feedback / comments on the whole issue in this thread of via email


Doug

I have always intended this place to be visible and readable to non-members so that anyone can dip in and out, and that the information built up over time would get archived at Google and other search engines for other people to use in the future.

However - on Tuseday night when I re-ordered and re-catagorised forums and subforums I forget to tick the boxes to allow thread views by guests.

This meant that until I fixed it late last night - some threads were not readable for non members - hands up - a big 'sorry - my bad' for that one.

On the upside - it answered a question I've been wondering for a while - how many guests are visiting the forum? Well - a few people saw that change and registered so they could view the content. I say a few, 103 of you in about 48 hrs actually. It increased total membership by about 30%!

Give that stat - I think it's fair to estimate that about 50% of the people visiting here are not actually members, just 'occasional lurkers' - and I'm sure there are some interesting people amoung those ranks of lookers-in.

So - a quick favour to ask - essentially as a nice shot in the arm for me and my little forum - if you are involved in any of the missions listed here, or even involved in one that isnt, I would LOVE to here from you via email ( doug@rlproject.com ) . This isnt so I can go "Oh - look, the PI for X is visiting..ner ner ner" - but simply so I know that I'm going in the right direction with this place.

Mission personnel are hellishly busy people with little time to eat, sleep and acknowledge the existance of their own families - let alone register and post in the place like this - but a few of you have and for those that have I am very VERY greatfull - your involvement gives some validity and grounding to this place.

As many will know - I'm hoping to put a book together of MER images in the not too distant future ( once the wheels have fallen off them - dont want to publish a book then have Opportunity take the panorama to beat all panoramas thereafter ) in the same mould as Full Moon - and acknowledgement of my imagery from 'industry' people would be a very usefull and powerfull tool in my quest to get the work of scientists and engineers into print in a fitting, beautiful and just manor.

Likewise - if you are involved in a mission of some sort and would like to say something without actually registering for fear of getting bombarded by 'fan mail' as it were - simply drop me a note and I can put your message across.

For those that would like to take the time to visit, register and contribute, I can set you as a moderator of a forum about your work so that if things are untoward w.r.t. what's being said, you can turn a post 'off' for editing etc. If you would like to have an @unmannedspaceflight.com email address that you can essentially ignore, but register with - let me know !

I'm off to the BAA meeting in London on Sat - to talk about the journey of Spirit - and that experience of talking about and sharing the spirit of discovery and exploration that MER has exemplified so very well is the very heart of what this place is about. It's about sharing, learning, teaching, creating, explorting - and to the people who have contributed so well in the past, and to those yet to contribute, I am for ever greatfull!

Doug

We've never seen a damaged rover wheel

Catapillar tracks are a route to disaster - overly complex - unable to navigate over the sorts of rocks that a 6 wheel rocker bogie system can - liable to trap dust etc.

imho - if skycrane hovers statically at 10m, and lowers the rover at 1 m/s - I see no reason for concern. Attention should be given to make the system robust and reliable at delivering the payload to the ground in a gentle and predictable manor. We shouldnt spend that time designing around shortcomings that shouldnt exist. i.e. cure the problems the system may have - dont patch up around the symptoms it may exhibit.

Doug

I wonder if the effects of looking thru narrow spectral bands will result in the sort of quality we get at Titan - or something a bit better than that

Doug

Yup - down the entry ramp at B would make sense to me - I'll try and fudge a 3d image of what I think it may be a bit like - but I wouldnt go much further in that that - as that would be death wish.

Doug

Essentially we HAVE the radar dataset and unless we go back with some enormous power-eating SAR to remap venus - it makes more sense to go back and start looking in other ways.

Doug

LOL - the JPL PAO playing catch up

http://marsrovers.jpl.nasa.gov/gallery/pre.../20050420a.html

I prefer mine

Doug

Wow - yeah - an excellent drive imho - Meth and LL now line up

http://marsrovers.jpl.nasa.gov/gallery/all...GEP0605L0M1.JPG

Doug

Surely the weight of any sled would be better spent on making the rovers rocker-bogie and wheels a little stronger so they can withstand any expected impact themselves?

Doug

That is the worst reporting I have ever seen - it goes on and on about explosives.

IT'S NOT GOING TO EXPLODE!!!

"a “fly-by” spacecraft and a smaller “impactor” carrying some 350 kilograms of a copper-based explosive"

WAHGHAH - it's just a lump of copper!!

Almost as much of a loonie as the person making the claim...
"
“I am not a scientist,” Molokhov says, “but experts say the impact could disrupt the comet’s plasma trail, which could have an effect on satellite communications.”
"

Bwhaa haaaaaaagaaaaa ha ha ha ha
Doug

lips=sealed

I was at the Natural History Museum, London last Thursday - and found a very large and very quiet mineral collection - and set out to find two things - hematite and concretions...

Concretions




Hematite






Mars Meteorite


The variety and beauty of some of the items in the collection at the NH museum is just astonishing - I intend a repeat visit when I get the chance to hunt down Goetite and Olivine, but I left the place thinking, if you had the polishing tools and a small drill, you could make a lovely necklace out of Meridiani Blueberries

Doug